One in six Americans will experience some kind of foodborne illness this year, according to the Centers for Disease Control and Prevention (CDC). If you’re affected, you’ll most likely have stomach upset, rash, headache, or diarrhea. But a minority will contract a more severe infection that can lead to protracted illness, disability and even death.

A recent report from the University of Florida’s Emerging Pathogens Institute identifies causes of foodborne illness – 10 specific pathogen-food combinations that pose the greatest threat to public health. The research addresses short- and long-term costs, such as medical expenses and lost work time, as well as pain and suffering.

Hopefully, this report will allow public health agencies to better focus their prevention efforts on food contaminants that have the greatest impact on human health. Knowing the type of pathogen and its food source allows food-safety experts to customize their approach to prevention.

Considering the economic impact – over a billion dollars a year – and the quality of life significantly affected from each pathogen, stakes are high in getting preventive efforts just right. While economic impact is easily measured through dollars expended or lost, quality of life can be more difficult to assess.

Impact on quality of life is measured through something called “lost quality adjusted life years,” or QALYs. Researchers add up total days of illness caused by a particular pathogen-food combination – including lost personal, family and work time from illness – and report the national total in terms of years.

For example, the top pathogen in terms of both cost and QALYs is campylobacter-contaminated poultry, costing $1.3 billion and 9,500 lost QALYs annually. The next three on the list are toxoplasma in pork at $1.2 billion and 4,500 lost QALYs; listeria in deli meats at $1.1 billion and 4,000 lost QALYs; and salmonella in poultry at $700 million and 3,600 lost QALYs.

Besides pork, toxoplasma-beef makes the top 10 list. Listeria appears on the list in combination with dairy products. Salmonella is also reported in combination with produce and complex (processed) foods. In all, the top 10 cost $8.6 billion, and perhaps most significantly, 33,600 lost QALYs each year.

Let’s take a brief look at the top three – campylobacter-poultry, toxoplasma-pork and listeria-deli meats.

Campylobacter is an infectious disease caused by bacteria. Even a single drop of contaminated raw poultry juice can infect a human. Most cases are associated with eating raw or uncooked poultry. Outbreaks of campylobacter are often associated unpasteurized milk or contaminated water. Most infected people experience diarrhea, cramping, abdominal pain, and fever within 2-5 days of exposure. The illness can last a week and may be fatal for people with compromised immune systems.

Toxoplasmosis is the leading cause of death attributed to foodborne illness in the U.S. More than 60 million adults and children carry the toxoplasmosis parasite, but few have symptoms because the immune system keeps it in check. It can affect most organ systems, including the brain, and flare in those with compromised immune systems. Transmission is from contaminated food, but also from animals (typically cats) and mother to child (congenital) transmission.

Listeria is a bacterial species that lives in soil and can easily contaminate cow udders and transfer into drinking milk if not pasteurized. Listeria is also dangerous, as it can grow at refrigerator temperatures without altering the smell or taste of food. Milk, cheese and deli meats, even if refrigerated, can infect humans if contaminated with listeria. Pregnant women and their fetuses, children and elderly are particularly vulnerable.